CN107432040B

CN107432040B - Device-based two-stage random resource selection for small data transmissions

Info

Publication number: CN107432040B
Application number: CN201680015050.4A
Authority: CN
Inventors: W·曾; J·B·索里亚加; T·姬; J·E·斯密; N·布衫
Original assignee: Qualcomm Inc
Current assignee: Qualcomm Inc
Priority date: 2015-03-14
Filing date: 2016-03-09
Publication date: 2020-12-08
Anticipated expiration: 2036-03-09
Also published as: EP3272175B1; US10051636B2; KR20170128310A; US20160270083A1; BR112017019606A2; WO2016148996A1; CN107432040A; EP3272175A1; JP2018511987A; JP6469247B2; KR102014009B1

Abstract

Wireless communication systems and methods are disclosed that relate to reducing the collision probability of grant-less transmissions from internet of everything (IOE) devices while not increasing the search complexity at the base station. The IOE device randomly selects a first access resource from a common pool searched by the base station to initiate a transmission. The IOE device also randomly selects a second access resource from a collision reduction pool for which the base station does not search if a metric associated with the data transmission is predicted to exceed a threshold. The IOE device informs the base station in the data transmission to switch to the selected second access resource included in the data transmission after a fixed period of time. After the specified period of time, the base station and the IOE device switch to the second access resource and complete the data transmission.

Description

Device-based two-stage random resource selection for small data transmissions

Cross Reference to Related Applications

This application claims priority from U.S. non-provisional patent application No.15/048,254 filed on 19/2016 and the benefit of U.S. provisional patent application No.62/133,343 filed on 14/3/2015, each of which is incorporated herein by reference in its entirety.

Technical Field

The present application relates to wireless communication systems, and more particularly to improving uplink communications from communication devices, such as "internet of everything" (IOE) devices, to base stations (or other communication devices) capable of accessing a shared pool of access resources.

Introduction to the design reside in

Data traffic on networks, such as cellular networks, has grown rapidly in recent years. This growth is fueled by the ever-increasing functionality of conventional mobile devices (such as cellular/smart phones) and other connected devices (such as tablets, laptops, and "smart terminals," such as IOE (also known as "internet of everything") devices). Some examples of smart terminals include devices that integrate sensors or meters to capture information that is then relayed to a remote system, such as a central server. This may include: smart metering, temperature monitoring, pressure monitoring, fluid flow monitoring, inventory monitoring, water level monitoring, equipment monitoring, healthcare monitoring, field survival monitoring, weather and geographic event monitoring, queue management and tracking, remote security sensing, physical access control, transaction-based business charging, and other applications.

Before these devices can transmit any data on the network, they must establish a radio link connection with the network, which includes a longer signaling procedure to request use of access resources (e.g., time and/or frequency elements in a resource block) and subsequent grants of access resources from the base station. The amount of overhead and/or time required to establish a radio link connection using an access request/grant approach becomes a problem for IOE devices, which are typically (given their nature) embedded with devices or objects that are typically designed to consume a small amount of power and have a low cost. For example, IOE devices (such as smart meters for utilities) may be expected to last for years without replacement or recharging (if recharging is possible).

Brief summary of some embodiments/examples

The following presents a simplified summary of some aspects of the disclosure in order to provide a basic understanding of the discussed technology. This summary is not an extensive overview of all contemplated features of the disclosure, and is intended to neither identify key or critical elements of all aspects of the disclosure, nor delineate the scope of any or all aspects of the disclosure. Its sole purpose is to present some concepts of one or more aspects of the disclosure in a general form as a prelude to the more detailed description that is presented later.

Instead of access request/grant, implementing a grant-less transmission scheme may be more energy efficient. For grantless transmissions, the IOE device directly begins transmitting its data (which is typically small in amount compared to voice/video and so on) without waiting for the base station (or other network element) to assign access resources. To achieve this, a common pool may be maintained with a limited number of access resources (such as frequencies, time slots, and/or codewords) that the IOE device uses to select one or more access resources from to begin grantless transmissions.

While the probability of two or more IOE devices selecting the same access resource(s) from a common pool at the same time (referred to as "collision") may be relatively low, situations sometimes arise where this probability is changed. For example, IOE devices that suffer from a large amount of path loss (such as due to being located far from a base station and/or being deployed in a high attenuation environment (such as a basement or other structure (s)) require significantly longer transmission times than other IOE devices accessing the same shared pool of access resources. As a result, IOE devices that require longer transmission times have a higher probability of colliding with new transmissions from other IOE devices that attempt to use the same access resource(s) from the common pool. While increasing the common pool size may help reduce the collision probability, this has the drawback of increasing the search complexity of the base station.

As a result, there is a need for techniques to reduce the probability of collisions while selecting access resources available in a common pool of access resources for grantless transmissions in a network (such as a cellular network) without increasing the search complexity at the base station. Various arrangements and embodiments of the technology discussed herein are intended to provide such aspects and features.

For example, in one aspect of the disclosure, a method for wireless communication includes: transmitting a first set of data from the first wireless communication device to the second wireless communication device using a first access resource selected from the shared pool of access resources as part of a grantless transmission; in response to determining that the grantless transmission exceeds a threshold, notifying, by the first wireless communication device, the second wireless communication device to transition to a second access resource selected from a collision reduction pool, the collision reduction pool being separate from and larger than the common pool; and transmitting, by the first wireless communication device, a second set of data to the second wireless communication device using the second access resource after transitioning to the second access resource.

In an additional aspect of the disclosure, a method for wireless communication includes: searching, by a first wireless communication device, a common pool of access resources to recover a first set of data received from a second wireless communication device using a first access resource selected from the common pool of access resources as part of a grantless transmission; receiving, at the first wireless communication device, a notification from the second wireless communication device to transition to a second access resource selected from a collision reduction pool, the collision reduction pool being separate from and larger than the common pool; and switching to the second access resource at the first wireless communication device to recover a second set of data from the second wireless communication device without searching the collision reduction pool.

In an additional aspect of the disclosure, a first wireless communication device comprises: a processor configured to: selecting a first access resource from a common pool of access resources as part of a grantless transmission to a first wireless communication device, and selecting a second access resource from a collision reduction pool in response to determining that the grantless transmission exceeds a threshold, the collision reduction pool being separate from and larger than the common pool; and a transceiver configured to: transmitting a first set of data to the first wireless communication device using the first access resource, wherein, in response to the determination, a first subset of data includes a notification of a transition to the second access resource for the first wireless communication device, the transceiver further configured to: transmitting a second set of data to the first wireless device using the second access resource.

In an additional aspect of the disclosure, a first wireless communication device comprises: a transceiver configured to receive a first set of data from a second wireless communication device, wherein the first set of data is transmitted from the second wireless communication device using first access resources selected from a common pool of access resources as part of a grantless transmission; a search module configured to: searching the common pool of access resources to recover a first subset of data received from the second wireless communication device, wherein the transceiver is further configured to: receiving, from the second wireless communication device, a notification to transition to a second access resource selected from a collision reduction pool, the collision reduction pool being separate from and larger than the common pool; and a processor configured to: switching the transceiver to the second access resource to recover a second set of data from the second wireless communication device without searching the collision reduction pool.

In an additional aspect of the present disclosure, a computer-readable medium having program code recorded thereon includes program code, the program code comprising: code for causing a first wireless communication device to transmit a first set of data to a second wireless communication device using a first access resource selected from a shared pool of access resources as part of a grantless transmission; code for causing the first wireless communication device to notify the second wireless communication device to transition to a second access resource selected from a collision reduction pool that is separate from and larger than the common pool in response to determining that the grantless transmission exceeds a threshold; and code for causing the first wireless communication device to transmit a second set of data to the second wireless communication device using the second access resource after transitioning to the second access resource.

In an additional aspect of the present disclosure, a computer-readable medium having program code recorded thereon includes program code, the program code comprising: code for causing a first wireless communication device to search a common pool of access resources to recover a first set of data received from a second wireless communication device using a first access resource selected from the common pool of access resources as part of a grantless transmission; code for causing the first wireless communication device to receive a notification from a communication device to transition to a second access resource selected from a collision reduction pool, the collision reduction pool being separate from and larger than the common pool; and code for causing a handover at the first wireless communication device to the second access resource to recover a second set of data from the second wireless communication device without searching the collision reduction pool.

In an additional aspect of the disclosure, a first wireless communication device comprises: means for transmitting a first set of data to a second wireless communication device using a first access resource selected from a shared pool of access resources as part of a grantless transmission; means for notifying the second wireless communication device to transition to a second access resource selected from a collision reduction pool that is separate from and larger than the common pool in response to determining that the grantless transmission exceeds a threshold; and means for transmitting a second set of data to the second wireless communication device using the second access resource after transitioning to the second access resource.

In an additional aspect of the disclosure, a first wireless communication device comprises: means for searching a common pool of access resources to recover a first set of data received from a second wireless communication device using a first access resource selected from the common pool of access resources as part of a grantless transmission; means for receiving a notification from the second wireless communication device to transition to a second access resource selected from a collision reduction pool, the collision reduction pool being separate from and larger than the common pool; and means for switching to the second access resource to recover a second set of data from the second wireless communication device without searching the collision reduction pool.

Other aspects, features and embodiments of the disclosure will become apparent to those ordinarily skilled in the art upon review of the following description of specific exemplary embodiments of the disclosure in conjunction with the accompanying figures. While features of the disclosure may be discussed below with respect to certain embodiments and figures, all embodiments of the disclosure may include one or more of the advantageous features discussed herein. In other words, while one or more embodiments may have been discussed as having certain advantageous features, one or more of such features may also be used in accordance with the various embodiments of the present disclosure discussed herein. In a similar manner, although exemplary embodiments may be discussed below as device, system, or method embodiments, it should be understood that such exemplary embodiments can be implemented in a variety of devices, systems, and methods.

Brief Description of Drawings

Fig. 1 is a diagram of an example wireless communication environment, in accordance with various embodiments of the present disclosure.

Fig. 2 is a block diagram of an example wireless communication device in accordance with various embodiments of the present disclosure.

Fig. 3 is a block diagram of an example base station in accordance with various embodiments of the present disclosure.

Fig. 4 is a diagram illustrating a grant-less transmission according to various embodiments of the present disclosure.

Fig. 5 is a diagram illustrating access resource pools for grantless transmissions in accordance with various embodiments of the present disclosure.

Fig. 6 is a diagram of grant-less transmit communications between devices according to embodiments of the present disclosure.

Fig. 7 is a flow diagram illustrating an example method for reducing collisions in grantless transmissions in accordance with various embodiments of the present disclosure.

Fig. 8 is a flow diagram illustrating an example method for reducing collisions in grantless transmissions in accordance with various embodiments of the present disclosure.

Detailed Description

The detailed description set forth below in connection with the appended drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details in order to provide a thorough understanding of the various concepts. It will be apparent, however, to one skilled in the art that these concepts may be practiced without these specific details. In some instances, well-known structures and components are shown in block diagram form in order to avoid obscuring such concepts.

The techniques described herein may be used for various wireless communication networks such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA and other networks. The terms "network" and "system" are often used interchangeably. A CDMA network may implement radio technologies such as Universal Terrestrial Radio Access (UTRA), CDMA2000, and so on. UTRA includes wideband CDMA (wcdma) and other CDMA variants. cdma2000 covers IS-2000, IS-95 and IS-856 standards. TDMA networks may implement radio technologies such as global system for mobile communications (GSM). An OFDMA network may implement radio technologies such as evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11(Wi-Fi), IEEE 802.16(WiMAX), IEEE 802.20, Flash-OFDM, etc. UTRA and E-UTRA are part of the Universal Mobile Telecommunications System (UMTS). 3GPP Long Term Evolution (LTE) and LTE-advanced (LTE-A) are new releases of UMTS (e.g., 4G networks) that use E-UTRA. UTRA, E-UTRA, UMTS, LTE-A, and GSM are described in literature from an organization named "third Generation partnership project" (3 GPP). CDMA2000 and UMB are described in documents from an organization named "third generation partnership project 2" (3GPP 2). The techniques described herein may be used for the above-mentioned wireless networks and radio technologies as well as other wireless networks and radio technologies, such as next generation (e.g., 5 th generation (5G)) networks.

Embodiments of the present disclosure introduce systems and techniques for reducing the probability of collisions between communication devices. For example, certain features enable and provide for collision reduction of communications between different internet of things (IOE) devices participating in grant-less transmissions to a base station. This can be achieved without increasing the search complexity of the network-side component (e.g., at the base station). To achieve this, two different access resource pools are typically provided. The first pool is a common pool of access resources that the base station searches for, having a relatively small number of access resources. The second pool is an access resource collision reduction pool, which has a relatively large number of access resources, for which the base station does not search. Both are broadcast from the base station.

In some embodiments, an IOE device having data to send selects a first access resource from a common pool (e.g., randomly) for transmitting data to a base station in a grant-less transmission. If the IOE device predicts (e.g., based on some monitored downlink metric (s)) that the data transmission will not exceed a threshold (e.g., the Received Signal Strength (RSS) of the downlink channel is greater than a threshold, the signal-to-noise ratio (SNR) of the channel is greater than a threshold, the data size is less than a threshold amount, and/or the estimated or actual transmission time exceeds a predetermined amount), the IOE device initiates and completes the transmission using the first access resource.

The IOE device also selects a second access resource from the collision reduction pool (e.g., randomly) if the IOE device predicts that a data transmission (e.g., some predicted transmission metric) will exceed a threshold. The IOE device includes a second access resource as part of the notification in the transmission to the base station to instruct the base station to transition to the second access resource when communicating with the IOE device after a specified number of subframes.

After a specified number of subframes have elapsed, the IOE device and the base station transition to the second access resource and complete the transmission. By switching to the second access resource, an IOE device predicting a longer transmission time may reduce the probability that another IOE device will randomly select the same access resource from a smaller common pool before the IOE device has completed its transmission. Further, this can be achieved without increasing the search complexity at the base station (e.g., by adding more access resources to the collision reduction pool that is not searched rather than the common pool that is searched).

Fig. 1 illustrates a wireless communication network 100 in accordance with various aspects of the present disclosure. Wireless network 100 may include a number of base stations 104 and a number of User Equipment (UEs) 106, both within one or more cells 102, as illustrated in fig. 1. The communication environment 100 may support operation on multiple carriers (e.g., waveform signals of different frequencies). A multi-carrier transmitter can transmit modulated signals on the multiple carriers simultaneously. For example, each modulated signal may be a multicarrier channel modulated in accordance with the various radio technologies described above. Each modulated signal may be sent on a different carrier and may carry control information (e.g., pilot signals, control channels, etc.), overhead information, data, and so on. The communication environment 100 may be a multi-carrier LTE network that is capable of efficiently allocating network resources. The communications environment 100 is one example of a network to which various aspects of the present disclosure apply.

The base station 104 as discussed herein may have various characteristics. In some scenarios, for example, the base station 104 may comprise an evolved node B (eNodeB) in the LTE context. The base stations 104 may also be referred to as base transceiver stations or access points. It will be appreciated that there may be one to many base stations, and that there may be different types of classifications, such as macro, pico and/or femto base stations. Base stations 104 may communicate with each other and other network elements via one or more backhaul links. The base station 104 communicates with the UE 106 as shown, including via a direct wireless connection or indirectly (e.g., via a relay device). The UE 106 may communicate with the base station 104 via the uplink and the downlink. The downlink (or forward link) refers to the communication link from the base stations 104 to the UEs 106. The uplink (or reverse link) refers to the communication link from the UEs 106 to the base stations 104.

The UEs 106 may be dispersed throughout the wireless network 100, and each UE 106 may be stationary or mobile. A UE may also be referred to as a terminal, mobile station, subscriber unit, etc. The UE 106 may be a cellular phone, a smart phone, a personal digital assistant, a wireless modem, a laptop computer, a tablet computer, an entertainment device, a medical device/equipment, a biometric device/equipment, a fitness/sports device, an onboard component/sensor, and so forth. The wireless communication network 100 is one example of a network to which various aspects of the present disclosure are applied.

In accordance with embodiments of the present disclosure, some UEs 106 may be internet of everything (IOE) devices, and reference will be made herein to IOE devices 106, although it will be appreciated that this is done for simplicity purposes only, and that base stations 104 may communicate with various different types of devices at the same or different times. More or fewer IOE devices 106 than those illustrated 106 may be deployed within the communication environment 100. The IOE device 106 may be stand-alone or integrated within other devices. The IOE device 106 may capture information that is then relayed to a remote system. The IOE devices 106 may have limited power resources because they are integrated with devices or objects to render those devices or objects "intelligently" and need to be able to operate for long periods of time without replacement or recharging (e.g., days, weeks, months, or years). As a result, the IOE device 106 may synchronize with beacons that the base station 104 periodically transmits. As a result of this synchronization, each IOE device 106 may wake up only at predefined time intervals according to the beacon in order to reduce power consumption. In addition to communicating with the base stations 104, the IOE devices 106 may also be capable of linking with each other, e.g., via D2D (e.g., peer-to-peer and/or mesh) links.

The techniques described herein may be used for single-input single-output (SISO) systems, single-input multiple-output (SIMO) systems, multiple-input single-output (MISO) systems, and multiple-input multiple-output (MIMO) systems. These techniques may be used for non-orthogonal based systems and for other multicarrier communication systems. Further, embodiments of the present disclosure relate to any type of modulation scheme, but use non-orthogonal waveforms for purposes of illustration. Non-orthogonal waveforms are useful according to embodiments of the present disclosure, as IOE devices 106 tend to have only a small amount of data to transmit during a given awake period, and other types of modulation will consume significantly more overhead and other resources, prematurely draining the battery life of the IOE devices 106. Furthermore, IOE devices 106 typically operate at a low power range, so that the interference in the shared frequency/time slot is less than would occur with a more powerful UE 106. For example, where the cell 102 is large and the frequency band has been dedicated to IOE device communication, non-orthogonal waveforms that rely on scrambling codes or interleaving may be used. For example, in an environment where the cell 102 has a small coverage area and the IOE device 106 shares the same bandwidth with other competing devices (such as other types of UEs), frequency may be relied upon.

As will be discussed in more detail below, the IOE device 106 first initiates a grantless transmission by selecting (e.g., randomly) an access resource from a shared pool of access resources. Since other IOE devices 106 accessing the same base station 104 randomly select from the same common pool (and, for example, do not participate in carrier sensing because the IOE devices 106 may be distributed far enough apart that carrier sensing is undesirable and/or impossible), there is a probability of collision that two IOE devices 106 randomly select the same access resource from the common pool. Typically, the data sent by the IOE device 106 with the grantless transmission is small enough (e.g., hundreds of bytes) so that the IOE device 106 uses the selected access resource for a short duration even with relatively low data rates (and thus, there is a low probability that another IOE device 106 will randomly select the same access resource during the grantless transmission).

However, situations may arise where the transmission may last longer, which increases the probability of an access collision with another IOE device 106 that may randomly select the same access resource before the first IOE device 106 has completed its grantless transmission. This may occur, for example, where the connection with the base station 104 is poor (e.g., significant path loss between the IOE device 106 and the base station 104, or the IOE device 106 is located in a high attenuation environment), the number of active devices within the cell, and the traffic pattern per device increases, to name a few examples.

To address this issue, the shared pool of access resources may be increased to have more access resources available for random selection. This reduces the probability of collision when each IOE device 106 randomly selects an access resource from the common pool. However, as the number of access resources in the shared pool increases, the search complexity of the base station also increases, which becomes undesirable. As used herein, search complexity refers to the need for repeatedly searching for different access resources (a combination of time and scrambling code/interleaving permutation, as discussed further below) when the base station 104 receives grant-less transmissions from various IOE devices 106 within its coverage. The base station 104 performs this search because, because of the grantless transmission, the base station 104 does not know when particular IOE devices 106 are awake or what access resources they select until the base station 104 receives the transmission. In an embodiment, the base station 104 searches by comparing the received grant-less transmission to each scrambling code or interleaver in the shared pool of access resources in order to detect which particular scrambling code or interleaver results in a high energy output.

Since the search complexity increases as the size of the shared pool of access resources increases, the shared pool of access resources can be kept at a manageable size, thereby obtaining an upper limit on the amount of search complexity at the base station, but limiting how much the collision probability can be reduced. To address this continuing need to reduce collision probability, embodiments of the present disclosure provide additional pools of access resource collision reduction. Continuing with the example of fig. 1, when a situation occurs in which the IOE device 106 determines that a grantless transmission will exceed some threshold metric (e.g., Received Signal Strength (RSS) of the downlink channel is less than a threshold, signal-to-noise ratio (SNR) of the channel is less than a threshold, data size is greater than a threshold amount, and/or estimated or actual transmission time exceeds a predetermined amount), then the IOE device 106 further randomly selects an access resource from the collision reduction pool.

When using access resources from the common pool, the IOE device 106 notifies the base station 104 of the selected access resource from the collision reduction pool and the specified number of subframes to wait before transitioning to the selected access resource from the collision reduction pool as part of the grantless transmission to the base station 104. In an alternative embodiment, the specified number of subframes may have been previously established or set in the network broadcast. After waiting a specified number of subframes, both the IOE device 106 and the base station 104 transition to an access resource selected from the collision reduction pool and continue communication until the data completes transmission.

According to embodiments of the present disclosure, the collision reduction pool helps to further reduce the probability of collisions between grantless transmissions of IOE devices 106 while still limiting the search complexity of the base station 104. This is because the base station 104 focuses its repeated searches on the common pool rather than the collision reduction pool, which may have a significantly larger amount of access resources than those available in the common pool.

Fig. 2 is a block diagram of an IOE device 106 according to embodiments of the disclosure. The IOE device 106 may have any one of many configurations described above for various IOE applications. The IOE device 106 may include a processor 202, a memory 204, a transmission access resource selection module 208, a transceiver 210, and an antenna 216. These elements may communicate with each other, directly or indirectly, for example, via one or more buses.

The processor 202 may include a Central Processing Unit (CPU), a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a controller, a Field Programmable Gate Array (FPGA) device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein with respect to the IOE device 106 introduced above with respect to fig. 1 and discussed in more detail below. The processor 202 may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

The memory 204 may include cache memory (e.g., cache memory of the processor 202), Random Access Memory (RAM), magnetoresistive RAM (mram), Read Only Memory (ROM), Programmable Read Only Memory (PROM), Erasable Programmable Read Only Memory (EPROM), electrically erasable read only memory (EEPROM), flash memory, solid state memory devices, hard drives, other forms of volatile and non-volatile memory, or combinations of different types of memory. In an embodiment, memory 204 includes a non-transitory computer-readable medium. The memory 204 may store instructions 206. The instructions 206 may include instructions that, when executed by the processor 202, cause the processor 202 to perform the operations described herein with reference to the IOE device 106 in connection with the embodiments of the present disclosure. The instructions 206 may also be referred to as code. The terms "instructions" and "code" may include any type of computer-readable statement(s). For example, the terms "instructions" and "code" may refer to one or more programs, routines, subroutines, functions, procedures, and the like. The "instructions" and "code" may comprise a single computer-readable statement or a plurality of computer-readable statements.

The transmission access resource selection module 208 may be configured to randomly select access resources from a common pool and randomly select access resources from a collision reduction pool, as described above with respect to fig. 1 and below with respect to fig. 5. The transmission access resource selection module 208 may randomly select access resources from the common pool for initiating a grant-less transmission to the base station 104. At the same time or at a later time, the transmission access resource selection module 208 may also randomly select access resources from the collision reduction pool. In response to first predicting or determining that data to be transmitted will take long enough to make collisions with other IOE devices 106 more likely (e.g., the other IOE devices 106 may randomly select the same access resource from a common pool before the IOE device 106 completes transmission of its data), the transmission access resource selection module 208 may select an access resource from a collision reduction pool.

For example, the transmission access resource selection module 208 may cooperate with other elements of the IOE device 106 to determine one or more parameters/metrics for one or both of the downlink from the base station 104 or the uplink to the base station 104. In one embodiment, the IOE device 106 monitors downlink information (e.g., one or more broadcast/beacon/other types of synchronization signals) from the base station 104 to determine the RSS and/or SNR of the downlink channel. The transmission access resource selection module 208 may use this information to predict the quality of the uplink channel (e.g., RSS, SNR, estimated total transmission time) before the IOE device 106 initiates a grant-less transmission to the base station 104. The transmission access resource selection module 208 may further compare the prediction to one or more thresholds and determine to also randomly select a second access resource from the collision reduction pool before initiating the grantless transmission. In an embodiment, the transmission access resource selection module 208 may select both access resources at or near the same time (from a common pool/collision reduction pool). With the selection made, the IOE device 106 may initiate a grantless transmission using a first access resource selected from the common pool. As part of the transmission, the transmission access resource selection module 208 may cause the selected second access resource (from the collision reduction pool) to also be included, along with a specified number of subframes (or time period, etc., to name two examples) prior to switching to the selected second access resource from the collision reduction pool.

As another example, transmission access resource selection module 208 may provide a first access resource selected from the common pool for initiating a grantless transmission without also selecting a second access resource from the collision reduction pool based on predicting that the transmission should have a sufficiently short duration with a lower probability of collision. However, when a transmission begins, the IOE device 106 may monitor the uplink to the base station 104 and, based on the uplink quality and/or transmission duration, determine during the transmission that the collision probability increases beyond a threshold level (e.g., by determining a signal metric, a data size metric, a transmission time metric, etc.). This may trigger the transmission access resource selection module 208 to select a second access resource from the collision reduction pool and to inform the base station 104 to switch to the selected second access resource from the collision reduction pool after a specified number of subframes during the transmission. In this way, selection from the collision reduction pool is delayed until the transmission access resource selection module 208 determines that switching may be useful for reducing the collision probability.

The transceiver 210 may include a modem subsystem 212 and a Radio Frequency (RF) unit 214. The transceiver 210 is configured to communicate bi-directionally with other devices, such as the base station 104. Modem subsystem 212 may be configured to: data from the memory 204 and/or the transmission access resource selection module 208 (and/or from another source, such as some type of sensor) is modulated and/or encoded according to a Modulation and Coding Scheme (MCS) (e.g., a Low Density Parity Check (LDPC) coding scheme, a turbo coding scheme, a convolutional coding scheme, etc.). The RF unit 214 may be configured to: process (e.g., perform analog-to-digital conversion or digital-to-analog conversion, etc.) modulated/encoded data from modem subsystem 212 (on an outgoing transmission) or a transmission originating from another source, such as base station 104. Although shown as being integrated together in the transceiver 210, the modem subsystem 212 and the RF unit 214 may be separate devices that are coupled together at the IOE device 106 to enable the IOE device 106 to communicate with other devices.

RF unit 214 may provide modulated and/or processed data, such as data packets (or more generally data messages that may contain one or more data packets or other information), to antenna 216 for transmission to one or more other devices. This may include, for example, transmitting data to the base station 104, in accordance with embodiments of the present disclosure. The antenna 216 may further receive data messages transmitted from the base station 104 and provide the received data messages for processing and/or demodulation at the transceiver 210. Although fig. 2 illustrates the antenna 216 as a single antenna, the antenna 216 may include multiple antennas of similar or different designs in order to maintain multiple transmission links.

Fig. 3 is a block diagram of an example base station 104 in accordance with various embodiments of the present disclosure. Base station 104 may include a processor 302, a memory 304, a resource coordination module 308, a transceiver 310, and an antenna 316. These elements may communicate with each other, directly or indirectly, for example, via one or more buses. The base station 104 may be an evolved node B (eNodeB), a macro cell, a pico cell, a femto cell, a relay station, an access point, or another electronic device operable to perform the operations described herein for the base station 104. The base station 104 may operate in accordance with one or more communication standards, such as a third generation (3G) wireless communication standard, a fourth generation (4G) wireless communication standard, a Long Term Evolution (LTE) wireless communication standard, an LTE-advanced wireless communication standard, or another wireless communication standard now known or later developed (e.g., a next generation network operating in accordance with a 5G protocol).

The processor 302 may include a CPU, DSP, ASIC, controller, FPGA device, another hardware device, firmware device, or any combination thereof configured to perform the operations described herein with reference to the base station 104 introduced in fig. 1 above. The processor 302 may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

The memory 304 may include cache memory (e.g., cache memory of the processor 302), RAM, MRAM, ROM, PROM, EPROM, EEPROM, flash memory, a solid state memory device, one or more hard drives, other forms of volatile and non-volatile memory, or a combination of different types of memory. In an embodiment, memory 304 includes a non-transitory computer-readable medium. The memory 304 may store instructions 306. The instructions 306 may include instructions that, when executed by the processor 302, cause the processor 302 to perform the operations described herein with reference to the base station 104 in connection with the embodiments of the present disclosure. The instructions 306 may also be referred to as code, which may be broadly interpreted to include any type of computer-readable statement(s), as discussed above with respect to FIG. 2.

The resource coordination module 308 may be operable to periodically or continuously search all scrambling codes, interleaver permutations, and/or frequencies maintained by the common pool (e.g., the copy stored in the memory 304 that matches the common pool stored at the IOE devices 106) in an attempt to identify data streams arriving from one or more IOE devices 106. According to embodiments of the present disclosure, the common pool is kept at a relatively small size in order to limit the search complexity (and corresponding computational resource utilization) imposed on the base station 104. As previously mentioned, the resource coordination module 308 (also referred to as the search module 308) focuses its search on the common pool and does not search the conflict reduction pool.

The transceiver 310 may include a modem subsystem 312 and a Radio Frequency (RF) unit 314. The transceiver 310 is configured to bidirectionally communicate with other devices, such as the IOE device 106 (and other types of UEs 106). The modem subsystem 312 may be configured to: the data is modulated and/or encoded according to an MCS (some examples of which have been listed above with respect to fig. 2). The RF unit 314 may be configured to: process (e.g., perform analog-to-digital conversion or digital-to-analog conversion, etc.) modulated/encoded data from modem subsystem 312 (on outgoing transmissions) or transmissions originating from another source, such as IOE device 106. Although shown as being integrated together in transceiver 310, modem subsystem 312 and RF unit 314 may be separate devices that are coupled together at base station 104 to enable base station 104 to communicate with other devices.

RF unit 314 may provide the modulated and/or processed data (e.g., data packets) to antenna 316 for transmission to one or more other devices, such as IOE device 106. The modem subsystem 312 may modulate and/or encode data in preparation for transmission. RF unit 314 may receive the modulated and/or encoded data packet and process the data packet before passing it to antenna 316. This may include, for example, transmitting a data message to the IOE device 106 or another base station 104, in accordance with embodiments of the present disclosure. As another example, this may also include broadcasting one or both of the common pool and the collision reduction pool to any IOE devices 106 (and/or other device types) within the broadcast range of the base station 104. The antenna 316 may further receive data messages transmitted from the IOE device 106 and/or other UEs 106 and provide the received data messages for processing and/or demodulation at the transceiver 310. Although fig. 3 illustrates the antenna 316 as a single antenna, the antenna 316 may include multiple antennas of similar or different designs in order to maintain multiple transmission links.

Fig. 4 is a diagram 400 illustrating a grant-less transmission according to various embodiments of the present disclosure. Fig. 4 illustrates four different IOE devices 106-IOE device 406 (user 1), IOE device 408 (user 2), IOE device 410 (user 3), and IOE device 412 (user 4) that initiate a grant-less transmission to base station 104. As will be appreciated, the four IOE devices shown are for ease of illustration, and more or fewer IOE devices may initiate grantless transmissions at a given point in time according to embodiments of the present disclosure.

As shown in fig. 4, a synchronization message 402a (e.g., a beacon) is transmitted from the base station 104, and the

IOE device

406 and 412 periodically wakes up and synchronizes with the synchronization message 402 a. In fig. 4, each of the

IOE devices

406 and 412 has data to transmit. After synchronization, each of the

IOE devices

406 and 412 randomly selects an access resource from the common pool. Since each access resource from the common pool has an access time associated with it, each

IOE device

406 and 412 may initiate its specific transmission at a different time.

For example,

IOE devices

406 and 408 begin their grantless transmissions at access time 404a because each IOE device randomly selects an access resource from the common pool that has the same access time 404 a. Since each

IOE device

406 and 408 randomly selects an access resource from the common pool, there is some probability that each IOE device will select the same access resource, but there is also some probability that they will not. Thus, although each

IOE device

406 and 408 selects an access resource from the common pool that has the same access time, they may still randomly select a different access resource from the common pool for a particular scrambling code or interleaver permutation associated with the access time.

Continuing with the example of fig. 4, the IOE device 410 begins its grantless transmission at access time 404b due to the random selection of an access resource with access time 404b from the common pool. Further, the IOE device 412 begins its grantless transmission at access time 404c due to the random selection of an access resource with access time 404c from the common pool. As illustrated in fig. 4, the total transmission time of the

IOE devices

406 and 410 is longer than the total transmission time of the IOE device 412.

Observing the IOE device 406 as a particular example, prior to initiating a transmission, the IOE device 406 may have predicted that a transmission metric for the transmission will exceed a predetermined threshold (e.g., based on RSS for the uplink, SNR, data size, bit rate, and/or total transmission time, such as estimated from downlink measurements, to name a few examples). As such, the IOE device 406 may select the second access resource from the collision reduction pool. The IOE device 406 may select the second access resource from the collision reduction pool before, after, and/or substantially simultaneously with selecting the access resource from the common pool. In the event that a transmission is initiated at access time 404a, the IOE device 406 may already include, as part of its data, a notification for the base station 104 to switch to a second access resource selected from the collision reduction pool (e.g., by including the selected second access resource and the number of subframes to delay before switching to occur). As a result, the base station 104 and the IOE device 406 communicate briefly using the first access resource from the common pool, but then switch to a second access resource selected from the collision reduction pool after a specified number of subframes (or a specified period of time) to continue transmitting data to the base station 104 until completion.

Looking now at the IOE device 412 as another specific example with a shorter transmission time, the IOE device 412 may have predicted that the transmission metric will not exceed the threshold before initiating the transmission. As a result, the IOE device 412 may initiate and complete a grant-less transmission of its data using only the access resources selected from the common pool.

As another example, prior to initiating the transmission, the IOE device 410 may initially predict (e.g., based on some measured quality of its downlink from the base station 104 and/or an amount of data to transmit) that the uplink will not exceed a predetermined threshold, and therefore does not select the second access resource from the collision reduction pool. However, when the transmission begins, the IOE device 408 may determine that there is asymmetry between the downlink and uplink such that the transmission via the uplink takes longer than predicted (and/or expected) time, increasing the probability of collision with another IOE device 106 that may subsequently wake up and randomly select the same access resource from the common pool. As a result, upon making this determination, the IOE device 410 may randomly select a second access resource from the collision reduction pool and notify the base station 104 of the selected second access resource from the collision reduction pool and the number of subframes to wait before switching to the selected second access resource. The IOE device 410 may then switch to the second access resource during the transmission, again reducing the probability of collision upon completion of the transmission.

Fig. 5 shows a diagram illustrating access resource pools for grantless transmissions in accordance with various embodiments of the present disclosure. In fig. 5, a shared pool of access resources 502 and a collision reduction pool of access resources are shown. The common pool 502 has a smaller number of access resources 504 than the collision reduction pool 506. Each access resource may be a pair of two resources, such as:

[ scrambling code, access time ]; or

[ interleaver, access time ].

A scrambling code is a particular sequence of bits that can be used to scramble data transmitted to the base station 104 (e.g., by multiplying the data bits with the scrambling code). The interleaver involves some permutation of the data bits being transmitted. These two pairs of alternatives are useful, for example, where non-orthogonal waveforms are used for grant-less transmission as described above. As will be appreciated, in embodiments where the cell 102 in fig. 1 is small, the other access resource may be a frequency, access time pair.

Returning to fig. 5, access resource collision reduction pool 506 is an additional pool of access resources 508 that is kept separate from common pool 502. As illustrated in fig. 5, access resources 508 in the collision reduction pool 506 are significantly more than access resources 504 in the common pool 502. As an example, there may be 10-30 times more access resources 508 in the collision reduction pool 506 (e.g., 16 or 32 access resources in the common pool 502 versus 500 to 1000 access resources in the collision reduction pool 506). This is by way of example only; as will be appreciated, other amounts may be maintained in each respective pool, with the number of access resources 508 in the collision reduction pool 506 being greater than the number of access resources 504 in the common pool 502). The access resources 508 in the collision reduction pool 506 may be in the same frequency band as the access resources 504 in the common pool 502 (e.g., where they are scrambling code or interleaver pairs), or alternatively in a different frequency band. In an embodiment, the common pool 502 and the collision reduction pool 506 do not share any common pair of access resources; thus, an IOE device 106 that has switched to using an access resource 508 from the collision reduction pool 506 will not have any probability of colliding with another IOE device 106 that randomly selects an access resource from the common pool 502, since there is no common pair of access resources between the two.

Both common pool 502 and collision reduction pool 506 may be received from base station 104 at some previous point in time, e.g., as part of a System Information Block (SIB) message. These pools may then be stored in the IOE device 106 (e.g., in the memory 204 described below with respect to fig. 2) and accessed as needed. These pools may remain static during transmission or alternatively be periodically updated with information received from the base station 104, e.g., as part of another SIB message.

An exemplary communication flow further illustrating the examples in fig. 4 and 5 is shown in fig. 6, fig. 6 illustrating a diagram of grantless transmission communications between an IOE device 106 and a base station 104 in accordance with embodiments of the present disclosure. As shown, fig. 6 illustrates communication after the IOE device 106 has received the synchronization message 402 (and after receiving a SIB that includes the common pool 502 and the collision reduction pool 506).

To begin grantless communications, the IOE device 106 randomly selects an ith access resource 504 from among the access resources 504 in the common pool 502 at act 602. The IOE device 106 initiates a grantless communication with the base station 104 using the selected access resource 504i at act 604 (e.g., beginning with

frames

0, 1, …, etc.). If the amount of data to be transmitted is small and/or the uplink is of sufficient quality, the transmission of the data takes a sufficiently small amount of time such that the IOE device 106 completes the grantless transmission using the selected access resource 504i without switching to the second access resource 508 from the collision reduction pool 506.

The amount of data to be transmitted may be large and/or the uplink quality is poor enough that the transmission of data may take more time and thus increase the collision probability. In embodiments where the situation is predicted to occur before the IOE device 106 initiates a grantless transmission, the IOE device 106 may also randomly select a second access resource 508q from among the access resources 508 in the collision reduction pool 506 before initiating a grantless transmission at act 606.

Where a second access resource 508q is also selected, the IOE device 106 may initiate a grantless transmission and include the selected second access resource 508q (along with the predetermined number of subframes to wait before the k-th subframe) with the transmission as part of act 604.

After the base station 104 receives the selected second access resource 508q (and the predetermined number of subframes in the message, unless the predetermined number of subframes is a value already stored at the base station 104 according to an embodiment), the base station 104 waits for the predetermined number of subframes. During this time, the IOE device 106 continues to transmit data in each subframe using the access resource 504 i. Once the predetermined number of subframes has been reached, the base station 104 switches to using the selected second access resource 508q at the kth subframe simultaneously with the IOE device 106 at act 608. The IOE device 106 then continues transmission using the selected second access resource 508q until the transmission is complete. As a result, the probability of collisions between IOE devices 106 selecting the same access resource 504 from the common pool 502 is further reduced, while also preventing the common pool 502 from becoming too large to place an excessive burden in terms of search complexity at the base station 104.

As an alternative example, embodiments of the invention may still be implemented in embodiments where the IOE device 106 does not predict a higher likelihood of a collision (e.g., based on a predicted transmission time or other transmission metric exceeding a predetermined threshold) before initiating the grantless transmission. For example, when starting a transmission using access resource 504i without otherwise selecting a second access resource 508 from the collision reduction pool, the IOE device 106 may monitor the uplink and/or transmission time and compare the metric to a threshold. If the threshold is exceeded, or predicted to be exceeded based on information of changes in the uplink and/or transmission time, the IOE device 106 may then proceed and select the second access resource 508q in action 606.

Once the second access resource 508q is selected, the IOE device 106 may include the selected second access resource 508q with the current data segment transmitted to the base station 104 (including the number of subframes to wait before making the handover) and notify the base station 104 of the intent to switch to the second access resource 508q at the kth subframe. Upon reaching the kth subframe, the base station 104 and the IOE device 106 may switch to the second access resource 508q, as described above.

Fig. 7 is a flow diagram illustrating an example method 700 for reducing collisions in grantless transmissions in accordance with various embodiments of the present disclosure. The method 700 may be implemented in the IOE device 106. For simplicity of discussion, the method 700 will be described with respect to a single IOE device 106, although it will be appreciated that the aspects described herein may be applicable to multiple IOE devices 106, including networks of IOE devices. It is understood that additional method blocks may be provided before, during, and after the blocks of method 700, and that some of the blocks described may be replaced or eliminated with respect to other embodiments of method 700.

In block 702, prior to initiating the grantless transmission, the IOE device 106 predicts a transmission metric for the uplink. For example, the IOE device 106 may use the transmission access resource selection module 208 in cooperation with other elements of the IOE device 106 to determine one or more parameters/metrics for the downlink from the base station 104. This may include, for example, monitoring downlink information (e.g., one or more broadcast/beacon/other types of synchronization signals) from the base station 104 to determine the RSS, SNR, bit rate, etc. of the downlink. The IOE device 106 may use this information to predict one or more transmission metrics for the uplink, including predicting an estimated time of transmission based on, for example, the data size and the predicted uplink metric (or measured downlink metric). Additionally or alternatively, the IOE device 106 may analyze the size of the data to be transmitted as a transmission metric.

At block 704, the IOE device 106 randomly selects a first access resource 504 from the shared pool of access resources 502. The IOE device 106 uses this first access resource 504 when beginning to transmit its data.

At decision block 706, the IOE device 106 determines whether the predicted transmission metric exceeds a threshold (which may involve a value above or below a threshold, depending on the threshold type). For example, the IOE device 106 may compare the predicted metric to one or more thresholds to help determine whether it may be useful to transition from a first access resource 504 from the common pool 502 to a second access resource 508 from the collision reduction pool 506 during a transmission. For example, the threshold may be an RSS threshold, an SNR threshold, a bit rate threshold, a data size threshold, and/or a predicted transmission time threshold, to name a few examples.

As a result of decision block 706, if it is determined that the predicted metric exceeds the threshold, the method 700 proceeds to block 708. At block 708, the IOE device 106 randomly selects a second access resource 508 from the collision reduction pool 506, which, as described above, may be significantly larger for the collision reduction pool 506 than the common pool 502. In an embodiment, the IOE device 106 may select both access resources 504/508 at the same time or nearly the same time, while in other embodiments the procedure may be sequential.

At block 710, the IOE device 106 includes a notification with the data to be transmitted that identifies the second access resource 508 selected at block 708. Further, the IOE device 106 may include a specified number of subframes that the IOE device 106 and the base station 104 need to wait before switching to the second access resource 508. In some embodiments, where the number of subframes is provided at both the IOE device 106 and the base station 104, the number of subframes need not be included, while in other embodiments the number of subframes is included.

At block 712, the IOE device 106 initiates a grant-less transmission with the base station 104 using the first access resource 504 selected at block 704. If it is determined at step 706 that the predicted metric exceeds or will exceed the threshold, the grantless transmission at block 712 may include a notification (from block 710) to the base station 104 to switch to the second access resource 508 (selected in block 708) at the kth subframe after the current subframe. If it is determined at block 706 that the predicted metric does not exceed or will not exceed the threshold, the method 700 may proceed to block 712 without selecting a second access resource 508 from the collision reduction pool 506 (block 708) and including a corresponding notification (block 710). As a result, blocks 708 and 710 may be omitted.

At decision block 714, if a handover is planned (e.g., second access resource 508 is selected and base station 104 is notified), the method 700 proceeds to decision block 716.

At decision block 716, the IOE device 106 determines whether the transmission has reached the kth subframe that is the designated point at which a handover to the second access resource 508 will occur. If the transmission has not reached the kth subframe, the method 700 returns to block 712 to continue transmitting data. If the transmission has reached the kth subframe, the method 700 proceeds to block 718.

At block 718, the IOE device 106 switches to the second access resource 508 (at the same subframe as the base station 104, as specified in the announcement or otherwise).

At block 720, the IOE device 106 continues to transmit data using the second access resource 508 instead of the first access resource 504. The IOE device 106 may continue to transmit data using the second access resource 508 until the transmission is complete.

Returning to decision block 714, if a switch is not planned, the method 700 proceeds to optional block 722 or block 726. At block 726, the IOE device 106 completes transmitting data using the first access resource 504. This may occur, for example, because the amount of data is small and/or the transmission time (based on, for example, uplink quality and/or data size) does not exceed a time threshold, and thus there is no increased probability of collision (as would occur with transmissions that take longer).

Focusing now on optional block 722, during a transmission using the first access resource 504, it is also possible that the IOE device 106 may still determine (dynamically during the transmission) that a certain transmission metric (or metrics) has exceeded or is predicted to exceed one or more thresholds. Accordingly, at block 722, the IOE device 106 determines a transmission metric. To this end, the IOE device 106 may monitor the uplink to the base station 104 and determine one or more transmission metrics, such as those described at block 702, based on the uplink quality and/or transmission duration.

At optional decision block 724, the IOE device 106 determines whether the measured (or predicted/calculated) metric exceeds a threshold, similar to that described above for decision block 706. In this manner, the IOE device 106 determines whether the metric (and indirectly, the collision probability) has transitioned (or is predicted to transition) beyond a threshold level during transmission (e.g., by determining a signal metric, a data size metric, a transmission time metric, etc.).

If the metric exceeds (or is now predicted to exceed) the threshold, the method 700 proceeds to block 708, where the IOE device 106 randomly selects the second access resource 508 from the collision reduction pool 506 and proceeds as described above with respect to block 708 and 714, and so on.

Returning to optional decision block 724, if the metric does not exceed (or is not predicted to exceed) the threshold, the method 700 proceeds to block 726, which operates as described above.

As a result of the above, the collision probability is significantly reduced, since the pool of available access resources in the collision reduction pool 506 is larger compared to the number of available access resources in the common pool 502. Furthermore, this is achieved without significantly increasing the search complexity at the base station 104, because the base station 104 still searches the common pool 502 without including the collision reduction pool 506, wherein the common pool 502 has not yet been enlarged.

Fig. 8 is a flow diagram illustrating an example method 800 for reducing collisions in grantless transmissions in accordance with various embodiments of the present disclosure. The method 800 may be implemented in the base station 104. For simplicity of discussion, the method 800 will be described with respect to a single base station 104 in communication with a single IOE device 106, although it will be recognized that the aspects described herein may be applicable to multiple IOE devices 106 and/or base stations 104. It is understood that additional method blocks may be provided before, during, and after the blocks of method 800, and that some of the blocks described may be replaced or eliminated with respect to other embodiments of method 800.

At block 802, the base station 104 receives a grant-less transmission from the IOE device 106 using the first access resource. As described above for the figures, the IOE device 106 randomly selects the first access resource 504 from the common pool 502, where the base station 104 may have previously transmitted the common pool (and the collision reduction pool 506) at some previous point in time, for example as part of a System Information Block (SIB).

At block 804, base station 104 searches common pool 502 to identify first access resources 504 for transmitting data from common pool 502 (and thereby enable processing of the transmission). According to embodiments of the present disclosure, the number of access resources in the common pool 502 is kept at a manageable amount in order to prevent the search complexity from increasing for the base station 104. The base station 104 performs this search because, because of the grantless transmission, the base station 104 does not know when particular IOE devices 106 are awake or what access resources they select until the base station 104 receives the transmission. In an embodiment, the base station 104 searches by comparing the received grant-less transmission to each scrambling code or interleaver in the shared pool of access resources to detect which particular scrambling code or interleaver has a high energy output.

At decision block 806, the base station 104 determines whether a notification to switch to the second access resource 508 from the collision reduction pool 506 is included in the transmission from the IOE device 106.

If a notification is included, the method 800 proceeds to block 808, where the base station 104 receives data in a transmission over multiple subframes while tracking the subframes. If no notification is included, the method 800 proceeds to decision block 818, where the base station determines whether the data transmission has been completed. If the data transmission has not been completed, the method 800 returns to block 802 to continue receiving grantless transmissions and proceeds as described above (and further described below). Conversely, if the data transfer has been completed, the method 800 proceeds to block 816 and ends.

Returning to block 808, method 800 proceeds to decision block 810. At decision block 810, the base station 104 determines whether the transmission has reached the kth subframe (the point specified in the notification at which a handover to the second access resource 508 will occur). If the transmission has not reached the kth subframe, the method 800 returns to block 808 to continue receiving data in the transmission. If the transmission has reached the kth subframe, the method 800 proceeds to block 812.

At block 812, the base station 104 switches to the second access resource 508 identified in the notification.

At block 814, the base station 104 continues to receive data in the transmission using the second access resources 508 until the transmission is complete, at which point the method 800 proceeds to block 816 and ends.

As a result of the above, the base station 104 avoids further increasing the search complexity because the common pool 502 is kept at a manageable size, while the collision probability is significantly reduced because the pool of available access resources in the collision reduction pool 506 (which the base station 104 does not search for) is larger than the number of available access resources in the common pool 502. Further, both common pool 502 and collision reduction pool 506 may be broadcast from base station 104, e.g., before and/or after the above elements (such as to provide updated pool information).

Information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

The various illustrative blocks and modules described in connection with the disclosure herein may be implemented or performed with a general purpose processor, a DSP, an ASIC, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration).

The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope of the disclosure and the following claims. For example, due to the nature of software, the functions described above may be implemented using software executed by a processor, hardware, firmware, hard-wired, or any combination thereof. Features that implement functions may also be physically located at various locations, including being distributed such that portions of functions are implemented at different physical locations.

Further, as used herein, including in the claims, "or" as used in a list of items (e.g., a list of items in a phrase such as with "at least one of or" one or more of) indicates an inclusive list, such that, for example, a list of "A, B or at least one of C" means a or B or C or AB or AC or BC or ABC (i.e., a and B and C). It is also contemplated that the features, components, acts, and/or steps described in connection with one embodiment may be structured in a different order than as presented herein and/or combined with the features, components, acts, and/or steps described in connection with other embodiments of the disclosure.

Embodiments of the present disclosure include a computer-readable medium having program code recorded thereon, the program code comprising: code for causing a first wireless communication device to transmit a first subset of data to a second wireless communication device using a first access resource selected from a shared pool of access resources as part of a grantless transmission. The program code further includes: code for causing the first wireless communication device to notify the second wireless communication device to transition to a second access resource selected from a collision reduction pool, the collision reduction pool being separate from the common pool, in response to determining that the grantless transmission exceeds the threshold. The program code further includes: code for causing the second wireless communication device to transmit a second subset of data to the second wireless communication device using the second access resource after transitioning to the second access resource.

The computer readable medium further comprises: code for causing the first wireless communication device to notify the second wireless communication device to transition to the second access resource after a fixed number of subframes after which the first wireless communication device begins transmitting the second subset of data. The computer readable medium further comprises: the apparatus generally includes means for selecting a first access resource by a first wireless communication device and means for selecting a second access resource by the first wireless communication device. The computer readable medium further comprises: code for causing the first wireless communication device to select the first and second access resources prior to transmitting the first subset of data. The computer readable medium further comprises: wherein the first and second access resources are randomly selected from a common pool and a collision reduction pool, respectively. The computer readable medium further comprises: wherein copies of the common pool and the collision reduction pool are stored in a memory of the first wireless communication device. The computer readable medium further comprises: code for causing the first wireless communication device to complete the transmission using the second access resource, wherein the second subset of data comprises a remaining amount of data. The computer readable medium further comprises: the apparatus generally includes means for analyzing a downlink message from a second wireless communication device prior to initiating transmission of a first subset of data, means for predicting a transmission metric for transmission of the data based at least in part on the analysis of the downlink message, and means for comparing the predicted transmission metric to a threshold to determine whether the predicted transmission metric exceeds the threshold. The computer readable medium further comprises: the apparatus generally includes means for determining a transmission metric during transmission of a first subset of data, means for comparing the determined transmission metric to a threshold during transmission of the first subset of data to determine whether the determined transmission metric exceeds the threshold, means for selecting a second access resource in response to the comparing, and means for including a notification for transitioning the second wireless communication device to the second access resource as part of the first subset of data in response to the selecting. The computer readable medium further comprises: wherein the common pool of access resources and the collision reduction pool each comprise at least one of scrambling code/access time pairs or interleaver/access time pairs, and wherein the first wireless communication device comprises an internet of everything device and the second wireless communication device comprises a base station.

Embodiments of the present disclosure further include a computer-readable medium having program code recorded thereon, the program code comprising: code for causing a first wireless communication device to search a common pool of access resources to recover a first subset of data received from a second wireless communication device using a first access resource selected from the common pool of access resources as part of a grantless transmission. The program code further includes: code for causing the first wireless communication device to receive a notification from the second wireless communication device to transition to a second access resource selected from a collision reduction pool, the collision reduction pool being separate from the common pool. The program code further includes: code for causing the first wireless communication device to switch to a second access resource to recover a second subset of data from the second wireless communication device without searching a collision reduction pool.

The computer readable medium further comprises: wherein the notification comprises a fixed number of subframes to delay before transitioning to the second access resource. The computer readable medium further comprises: code for causing a first wireless communication device to receive a notification from a second wireless communication device as part of a first subset of data. The computer readable medium further comprises: code for causing the first wireless communication device to receive a notification using the first access resources after receiving at least a portion of the first subset of data. The computer readable medium further comprises: wherein the common pool of access resources and the collision reduction pool each comprise at least one of scrambling code/access time pairs or interleaver/access time pairs. The computer readable medium further comprises: code for causing a first wireless communication device to determine a range of access resources to include in a shared pool of access resources and in a collision reduction pool. The computer readable medium further comprises: code for causing a first wireless communication device to transmit the determined common pool of access resources and the collision reduction pool to a second wireless communication device, wherein the first wireless communication device comprises a base station and the second wireless communication device comprises an internet of everything device.

Embodiments of the present disclosure further include a first wireless communication device comprising: means for transmitting a first subset of data to a second wireless communication device using a first access resource selected from a shared pool of access resources as part of a grantless transmission. The first wireless communication device further comprises: means for notifying the second wireless communication device to transition to a second access resource selected from a collision reduction pool, the collision reduction pool being separate from the common pool, in response to determining that the grantless transmission exceeds the threshold. The first wireless communication device further comprises: means for transmitting, after transitioning to the second access resource, a second subset of data to the second wireless communication device using the second access resource.

The first wireless communication device further comprises: means for notifying the second wireless communication device to transition to the second access resource after a fixed number of subframes after which the first wireless communication device begins transmitting the second subset of data. The first wireless communication device further comprises: means for selecting a first access resource, and means for selecting a second access resource. The first wireless communication device further comprises: means for selecting the first and second access resources prior to transmitting the first subset of data. The first wireless communication device further comprises: wherein the first and second access resources are randomly selected from a common pool and a collision reduction pool, respectively. The first wireless communication device further comprises: wherein copies of the common pool and the collision reduction pool are stored in a memory of the first wireless communication device. The first wireless communication device further comprises: means for completing the transmission using the second access resource, wherein the second subset of data comprises a remaining amount of data. The first wireless communication device further comprises: the apparatus generally includes means for analyzing a downlink message from a second wireless communication device prior to initiating transmission of a first subset of data, means for predicting a transmission metric for transmission of the data based at least in part on the analysis of the downlink message, and means for comparing the predicted transmission metric to a threshold to determine whether the predicted transmission metric exceeds the threshold. The first wireless communication device further comprises: the apparatus generally includes means for determining a transmission metric during transmission of a first subset of data, means for comparing the determined transmission metric to a threshold during transmission of the first subset of data to determine whether the determined transmission metric exceeds the threshold, means for selecting a second access resource in response to the comparison, and means for including a notification for transitioning the second wireless communication device to the second access resource as part of the first subset of data in response to the selection. The first wireless communication device further comprises: wherein the common pool of access resources and the collision reduction pool each comprise at least one of scrambling code/access time pairs or interleaver/access time pairs, and wherein the first wireless communication device comprises an internet of everything device and the second wireless communication device comprises a base station.

Embodiments of the present disclosure further include a first wireless communication device comprising: means for searching a common pool of access resources to recover a first subset of data received from a second wireless communication device using a first access resource selected from the common pool of access resources as part of a grantless transmission. The first wireless communication device further comprises: means for receiving a notification from a second wireless communication device to transition to a second access resource selected from a collision reduction pool, the collision reduction pool being separate from the common pool. The first wireless communication device further comprises: means for switching to a second access resource to recover a second subset of data from a second wireless communication device without searching a collision reduction pool.

The first wireless communication device further comprises: wherein the notification comprises a fixed number of subframes to delay before transitioning to the second access resource. The first wireless communication device further comprises: means for receiving a notification from the second wireless communication device as part of the first subset of data. The first wireless communication device further comprises: means for receiving a notification using the first access resource after receiving at least a portion of the first subset of data. The first wireless communication device further comprises: wherein the common pool of access resources and the collision reduction pool each comprise at least one of scrambling code/access time pairs or interleaver/access time pairs. The first wireless communication device further comprises: means for determining a range of access resources to include in the shared pool of access resources and in the collision reduction pool. The first wireless communication device further comprises: means for transmitting the determined common pool of access resources and the collision reduction pool to a second wireless communication device, wherein the first wireless communication device comprises a base station and the second wireless communication device comprises an internet of everything device. The first wireless communication device further comprises: code for causing a computer to perform one or more of the aspects of the features described above.

As those of ordinary skill in the art will appreciate so far and depending on the particular application at hand, many modifications, substitutions, and variations may be made in the materials, devices, configurations, and methods of use of the apparatus of the present disclosure without departing from the spirit and scope of the present disclosure. In view of the above, the scope of the present disclosure should not be limited to the particular embodiments illustrated and described herein (as they are merely some examples of the disclosure), but rather should be fully commensurate with the appended claims and their functional equivalents.

Claims

1. A method for wireless communication, comprising:

transmitting, from the first wireless communication device to the second wireless communication device, a first set of data using a first access resource selected from the shared pool of access resources as part of a grantless transmission;

in response to determining that the grant-less transmission exceeds a threshold, selecting, by the first wireless communication device, a second access resource from a collision reduction pool configured to share resources in a grant-less transmission, wherein the collision reduction pool is separate from and larger than the common pool;

notifying, by the first wireless communication device, the second wireless communication device to transition to the second access resource selected from the collision reduction pool, the notification indicating the selected second access resource; and

transmitting, by the first wireless communication device, a second set of data to the second wireless communication device using the second access resource after transitioning to the second access resource.

2. The method of claim 1, wherein the notifying further comprises:

notifying the second wireless communication device to transition to the second access resource after a fixed number of subframes after which the first wireless communication device begins transmitting the second set of data.

3. The method of claim 1, further comprising:

selecting, by the first wireless communications device, the first access resource prior to transmitting the first set of data; and

selecting, by the first wireless communication device, the second access resource prior to transmitting the first set of data,

wherein the first access resource and the second access resource are randomly selected from the common pool and the collision reduction pool, respectively.

4. The method of claim 1, further comprising:

receiving the common pool and the collision reduction pool as part of one or more broadcasts from the second wireless communication device prior to transmitting the first set of data.

5. The method of claim 1, further comprising:

completing the transmission using the second access resource, wherein the second data set includes a remaining amount of data of the first data set.

6. The method of claim 1, wherein the determining comprises:

analyzing, by the first wireless communication device, a downlink message from the second wireless communication device prior to initiating transmission of the first set of data;

predicting, by the first wireless communication device, a transmission metric for transmission of data comprising the first set of data based at least in part on an analysis of the downlink message; and

comparing, by the first wireless communication device, the predicted transmission metric to a threshold to determine whether the predicted transmission metric exceeds the threshold.

7. The method of claim 1, further comprising:

determining, by the first wireless communication device, a transmission metric during transmission of the first set of data;

comparing, by the first wireless communication device, the determined transmission metric to a threshold during transmission of the first set of data to determine whether the determined transmission metric exceeds the threshold;

selecting, by the first wireless communication device, the second access resource in response to the comparison; and

include, as part of the first set of data, a notification for transitioning the second wireless communication device to the second access resource in response to the selection.

8. The method of claim 1, wherein:

the common pool of access resources and the collision reduction pool each comprise at least one of scrambling code/access time pairs or interleaver/access time pairs;

the first wireless communication device comprises an internet of everything device and the second wireless communication device comprises a base station; and

both the common pool and the collision reduction pool are shared among a plurality of internet of everything devices.

9. A method for wireless communication, comprising:

searching, by a first wireless communication device, a common pool of access resources to recover a first set of data received from a second wireless communication device using a first access resource selected from the common pool of access resources as part of a grantless transmission;

receiving, at the first wireless communication device, a notification from the second wireless communication device to transition to a second access resource selected from a collision reduction pool configured to share resources in grant-less transmissions, the notification indicating the selected second access resource, and the collision reduction pool being separate from and larger than the common pool; and

switching to the second access resource at the first wireless communication device to recover a second set of data from the second wireless communication device without searching the collision reduction pool.

10. The method of claim 9, wherein the notification comprises a fixed number of subframes to delay before transitioning to the second access resource.

11. The method of claim 9, wherein receiving the notification further comprises:

receiving the notification from the second wireless communication device as part of the first set of data.

12. The method of claim 9, wherein receiving the notification further comprises:

receiving the notification using the first access resource after receiving at least a portion of the first set of data.

13. The method of claim 9, wherein the common pool of access resources and the collision reduction pool each comprise at least one of scrambling code/access time pairs or interleaver/access time pairs.

14. The method of claim 9, further comprising:

determining a range of access resources to include in the common pool of access resources and the collision reduction pool.

15. The method of claim 14, further comprising:

broadcasting the determined common pool of access resources and the collision reduction pool from the first wireless communication device to the second wireless communication device, wherein the first wireless communication device comprises a base station and the second wireless communication device comprises an internet of everything device.

16. A first wireless communications device, comprising:

a processor configured to:

selecting a first access resource from the common pool of access resources as part of a grant-less transmission to the second wireless communication device; and

selecting a second access resource from a collision reduction pool configured to share resources in a grant-less transmission in response to determining that the grant-less transmission exceeds a threshold, the collision reduction pool being separate from and larger than the common pool; and

a transceiver configured to:

transmitting a first set of data to the second wireless communication device using the first access resource, wherein, in response to the determination, the first set of data includes a notification to transition the second wireless communication device to the second access resource, the notification indicating the selected second access resource; and

transmitting a second set of data to the second wireless communication using the second access resource.

17. The first wireless communications device of claim 16, wherein the processor is further configured to: including with the notification a fixed number of subframes to be delayed before transitioning to the second access resource.

18. The first wireless communications device of claim 16, further comprising:

a memory configured to store the common pool of access resources and the collision reduction pool, the common pool of access resources and the collision reduction pool each comprising at least one of scrambling code/access time pairs or interleaver/access time pairs,

wherein the processor is further configured to: randomly selecting the first access resource and randomly selecting the second access resource prior to transmitting the first set of data.

19. The first wireless communications device of claim 16, wherein the transceiver is further configured to:

receiving the common pool and the collision reduction pool as part of one or more broadcasts from the second wireless communication device prior to transmission of the first set of data.

20. The first wireless communications device of claim 16, wherein the transceiver is further configured to: completing transmission of the second set of data using the second access resource, wherein the second set of data includes a remaining amount of data.

21. The first wireless communications device of claim 16, wherein the processor is further configured to:

analyzing a downlink message from the second wireless communication device prior to initiating transmission of the first set of data;

predicting a transmission metric for transmission of data based at least in part on an analysis of the downlink message; and

the predicted transmission metric is compared to a threshold to determine whether the predicted transmission metric exceeds the threshold.

22. The first wireless communications device of claim 16, wherein the processor is further configured to:

determining a transmission metric during transmission of the first set of data;

comparing the determined transmission metric to a threshold during transmission of the first set of data to determine whether the determined transmission metric exceeds the threshold;

selecting the second access resource in response to the comparison; and

include the notification to transition the second wireless communication device to the second access resource as part of the first set of data in response to the selection.

23. The first wireless communications device of claim 16, wherein the first wireless communications device comprises an internet of everything device and the second wireless communications device comprises a base station, and both the common pool and the collision reduction pool are shared among a plurality of internet of everything devices.

24. A first wireless communications device, comprising:

a transceiver configured to:

receiving a first set of data from a second wireless communication device, wherein the first set of data was transmitted from the second wireless communication device using a first access resource selected from a common pool of access resources as part of a grantless transmission; and

receiving, from the second wireless communication device, a notification to transition to a second access resource selected from a collision reduction pool configured to share resources in grant-less transmissions, the notification indicating the selected second access resource, and the collision reduction pool being separate from and larger than the common pool; and

a processor configured to:

searching the common pool of access resources to recover the first set of data received from the second wireless communication device; and

switching the transceiver to the second access resource to recover a second set of data from the second wireless communication device without searching the collision reduction pool.

25. The first wireless communications device of claim 24, wherein said notification includes a fixed number of subframes to delay before transitioning to said second access resource.

26. The first wireless communications device of claim 24, wherein the transceiver is further configured to: receiving the notification from the second wireless communication device as part of the first set of data.

27. The first wireless communications device of claim 24, wherein the transceiver is further configured to: receiving the notification using the first access resource after receiving at least a portion of the first set of data.

28. The first wireless communications device of claim 24, wherein the common pool of access resources and the collision reduction pool each comprise at least one of scrambling code/access time pairs or interleaver/access time pairs.

29. The first wireless communications device of claim 24, wherein:

the processor is further configured to: determining a range of access resources to be included in the common pool of access resources and the collision reduction pool, and

the transceiver is further configured to: broadcasting the determined common pool of access resources and the collision reduction pool to the second wireless communication device.

30. The first wireless communications device of claim 24, wherein the first wireless communications device comprises a base station and the second wireless communications device comprises an internet of everything device.